<!DOCTYPE html>
<html>
    <head>
        <title>Example</title>
        <style type="text/css">
        /* 伪元素选择器 ::first-line 文本内容的首行
            伪元素选择器可以作为修饰符跟其他选择器一块儿使用，例如p::first-line
         */
            ::first-line{
                background-color: grey;
                color: white;
            }
        </style>
    </head>
    <body>
        <p>Fourscore and seven years ago our fathers brought forth
            on this continent a new nation, conceived in liberty, and
            dedicated to the proposition that all men are created equal.</p>
        
        <p>I like <span>apples</span> and oranges.</p>

        <a href="http://w3c.org">Visit the W3C website</a>
    </body>
</html>